When market participants of each NEMO submit orders, they are put together in one Shared Order Book (SOB). In a similar way, TSOs make available all the intraday cross-border capacities in the Capacity Management Module (CMM).  

This allows NEMOs to operate trading systems to show orders to market participants from other market participants in three groups:

• within the same NEMO
• from other NEMOs in the same market area
• from other market areas as long as there is enough capacity available

When a market participant submits an order for a different market area, it can be matched (i.e. met) as long as there is enough capacity available. To match an order simply means that the market participant can meet and supply the energy demand.

Trade is done on a first-come first-served principle where the highest buy price and the lowest sell price get served first.

Updating the SOB and CMM

When the order can be matched, the order matching is associated with implicit capacity allocation. (This is when capacity and energy are priced together.) While two orders are being matched, the SOB and CMM are updated immediately.

The update of the SOB means that the matched orders are removed from the SOB, and consequently the available transmission capacity in the CMM is updated. The number of borders that have their capacities updated depends on where the matched orders are located.

For borders where NRAs (National Regulatory Authorities) requested, explicit allocation is made available to explicit participants. Currently this is only at the French-German border.

How data about trades is used

The Shipping Module (SM) receives data from the SOB about all trades when they are concluded. These can be:

• between two different delivery areas, and
• in the same delivery area between two different NEMOs.

The Shipping Module (SM) of the SIDC Solution provides information from concluded trades to all relevant parties such as NEMOs and TSOs.

The data from the SOB and the CMM is enhanced with data from:

• the relevant TSO,
• the Central Counter Party (CCP), and
• shipping agent data from the Shipping Module (SM).

This enhanced data is then sent to relevant parties such as the NEMOs and TSOs at the configured moments.

Figure – Modules of SIDC technical solution